Water inlet construction for continuous-casting molds

ABSTRACT

A water inlet construction for continuous-casting molds to distribute cooling water more uniformly across the mold face, and a method of introducing water. The mold has a plurality of parallel vertically extending water circulation channels between its outer wall and liner. A single inlet serves several channels at each side, which is conventional. Invention is to interpose a baffle having sloping edges between the inlet and channels. The baffle directs water to the remote channels which otherwise do not receive proportional shares.

United States Patent 1191 Auman et a].

[ 1 WATER INLET CONSTRUCTION FOR CONTINUOUS-CASTING MOLDS [75] Inventors: Paul M. Auman, Franklin Township;

Hugh E. Pry, Trafford, North Huntington Township, both of Pa.

[73] Assignee: United States Steel Corporation, Pittsburgh, Pa.

22 Filed: Mar. 16, 1972 211 Appl. No.: 235,185

52 US. Cl. 164/82, 164/283 511 161.01 ..B22d 11/02 [58] Field 61 Search 164/82, 273 R, 283

[56] References Cited UNITED STATES PATENTS 3,049,769 Schultz 164/283 X Pearson 164/82 X Mallener 164/82 X Primary Examiner-R. Spencer Annear V Att0rneyWalter P. Wood 1 5 ABSTRACT A water inlet construction for continuous-casting molds to distribute cooling water more uniformly across the mold face, and a method of introducing water. The mold has a plurality of parallel vertically extending water circulation channels between its outer wall and liner. A single inlet serves several channels at each side, which is conventional. llnvention is to interpose a baffle having sloping edges between the inlet and channels. The baffle directs water to the remote channels which otherwise do not receive proportional shares.

4 Claims, 5 Drawing Figures PATENTEDUBT SHEET 10F 2 PATENIEUUBT v91m SHEE 2 UF 2 11/0073/1 an m ass VIII/IQ 7 Fmolds.

A conventional continuous-casting mold includes a tubular liner and outer walls surrounding the liner. Parallel vertically extending water circulation channels or passageways are formed between the outer walls and the liner along each face of the mold. Water is introduced to these channels through inlets near one end, usually the bottom, and discharges through outlets near the other end. The water cools the liner and aids in solidifying an outer skin on the casting as it passes through the mold. Each inlet serves a number of channels at both sides thereof, as well as channels directly in line therewith. There has been a problem that the water is not distributed uniformly among the channels, but tends to be concentrated in channels nearest the inlet, while the more remote channels do not receive proportionate shares. This results in non-uniform cooling of the casting and is detrimental to the quality of the product.

Others have recognized the problem of distributing water uniformly across passageways in a mold which has water inlets near the top. Harter et al US. Pat. No. 2,867,018 shows a mold equipped with a weir between a top inlet and a passageway through which a cooling fluid flows. The purpose of the weir is to distribute cooling fluid uniformly across the passageway. An equivalent structure applied to a bottom inlet for water may improve the distribution, but does not afford complete uniformity of water flow to all the channels, as hereinafter demonstrated.

An object of our invention is to provide, in a continuous casting mold of the type having a bottom inlet for water, an improved inlet construction which distributes water more uniformly among a group of parallel channels than arrangements known heretofore.

A more specific object is to provide an improved inlet construction in which we interpose a baffle having upwardly sloping lower edges between the actual inlet and the channels.

A further object is to provide a water circulation method which distributes water more nearly uniformly across the face of a continuous-casting mold.

In the drawings:

FIG. 1 is a side elevational view of the lower portion of a continuous-casting mold constructed in accordance with our invention;

FIG. 2 is a horizontal section on line lI-ll of FIG. 1;

FIG. 3 is a vertical section on line 1lI--lI1 of FIG. 2;

FIG. 4 is a vertical section on line lV-1V of FIG. 3; and

FIG. 5 is a series of curves comparing the water flow across the face ofa mold with different inlet constructions.

FIGS. 1, 2 and 4 show the lower portion of a continuous casting mold, which includes a tubular liner l0 and outer walls 12 fixed to the liner with studs 13 and nuts 14. Each outer wall has a respective water inlet 15, the center of which is located approximately on the vertical center line of the wall near the bottom. Each outer face of the liner has a plurality of parallel vertically extending water-circulation channels 16. The channels in line with the centers of the inlets are designated 16a and the most remote channels 16b. Each inlet leads to a respective chamber 17 which communicates with all the channels 16 at its face of the mold. The channels lead to outlets (not shown) located near the top of the mold. The structure thus far described is conventional. The particular mold illustrated is square in cross section for casting billets or blooms, but similar principles apply to molds for casting other shapes, such as slabs. In a slab mold the narrow end walls would appear similar to each wall of the mold illustrated, while the wide side walls would include a plurality of inlets leading to sepa rate water courses.

In accordance with our invention, we mount a respective baffle 20 on the inside face of each wall 12, as best shown in FIGS. 3 and 4. The baffle is located at the exit side of chamber 17 across the top thereof, where it is interposed between the actual inlet 15 and the channels 16. An important feature of the invention is that the baffle has lower edges 21 which slope upwardly in both directions from the vertical center line of the baffle at angles of about 5 to 15 with respect to the horizontal. The vertical center line of the baffle or the apex lies approximately on the center of the inlet 15. The baffle substantially covers the inlet when viewed from the inside as in FIG. 3. The effect of the baffle is to diminish the area through which water reaches channel 16a opposite the apex of the baffle, and proportionately increase the area through which water reaches the most remote channels 16b. Since the lower edges of the baffle slope, the area through which water flows from the chamber 17 to the channels is at a maximum opposite the most remote channels. The angle of slope is critical if uniform distribution is to be attained. 1f the angle is too small, the remote channels do not receive enough water. If too large, the remote channels receive too much water.

FIG. 5 shows a set of curves we obtained in tests with a mold constructed as shown in FIGS. 1 and 2. The abscissae represent the mold width and the ordinates the water velocity in feet per second. The points on the curves are taken at each channel 16, of which there were nine per side in the mold tested. Curve A shows the distribution without a baffle, Curve B the distribution with a baffle having a straight lower edge, and Curve C the distribution with a baffle the lower edges of which slope upwardly from the center at angles of 11 to the horizontal. In each instance we introduced water at a rate of gallons per minute through the inlet. We performed a number of tests with each construction, but the curves represent the best condition we attained with each. Curve A shows a water velocity of about 16.5 feet per second at the center channel, as against about 13 and l 1.5 at the two most remote channels. Curve B shows a water velocity of about 13 feet per second at the center channel, as against about 10.5 and less than 10 at the two most remote channels. Curve C shows a water velocity of 13 feet per second at the center channel, as against about 14 and 13 at the two most remote channels. Curve B represents a condition obtained with a construction equivalent to weir of the aforementioned l-Iarter et al patent, but applied to a bottom inlet.

From the foregoing description it is seen that our invention affords a simple construction and method for distributing water more uniformly across a mold face. As a result of using our invention, a casting formed in the mold cools more uniformly and is less velop defects.

We claim: 7

1. In a continuous-casting mold which includes a tubular liner and outer walls fixed to said liner, a face of which mold has a plurality of parallel vertically extending water-circulation channels between said wall and said liner, an inlet to said channels located near the bottom of the mold, and a chamber affording communication between said inlet and channels, said inlet serving a number of channels, some of which are approximately in line with the inlet and others of which are more remote therefrom at each side, the combination therewith of a construction for distributing water more uniformly among said channels, said construction comprising a baffle interposed between said liner and said wall across the top of said chamber, said baffle having lower edges which slope upwardly in each direction from an apex located approximately in line with the center line of said inlet.

likely to de- 2. A construction as defined in claim 1 in which said lower edges slope at an angle of about 5 to 15 to the horizontal.

3. A construction as defined in claim 1 in which said mold is square in cross section and which is duplicated at each face of the mold, said inlets being located approximately on the vertical center lines of the faces.

4. A method of introducing water to a plurality of parallel vertically extending channels in a continuouscasting mold from an inlet aligned with a channel near the center of the plurality, said method comprising introducing the water from the inlet first to a chamber which communicates with the lower ends of said passages, and distributing the water from said chamber through a relatively restricted area to the channels nearer the center and an increasing area to channels more remote from the center, whereby the water is distributed substantially uniformly among the channels. 

1. In a continuous-casting mold which includes a tubular liner and outer walls fixed to said liner, a face of which mold has a plurality of parallel vertically extending water-circulation channels between said wall and said liner, an inlet to said channels located near the bottom of the mold, and a chamber affording communication between said inlet and channels, said inlet serving a number of channels, some of which are approximately in line with the inlet and others of which are more remote therefrom at each side, the combination therewith of a construction for distributing water more uniformly among said channels, said construction comprising a baffle interposed between said liner and said wall across the top of said chamber, said baffle having lower edges which slope upwardly in each direction from an apex located approximately in line with the center line of said inlet.
 2. A construction as defined in claim 1 in which said lower edges slope at an angle of about 5* to 15* to the horizontal.
 3. A construction as defined in claim 1 in which said mold is square in cross section and which is duplicated at each face of the mold, said inlets being located approximately on the vertical center lines of the faces.
 4. A method of introducing water to a plurality of parallel vertically extending channels in a continuous-casting mold from an inlet aligned with a channel near the center of the plurality, said method comprising introducing the water from the inlet first to a chamber which communicates with the lower ends of said passages, and distributing the water from said chamber through a relatively restricted area to the channels nearer the center and an increasing area to channels more remote from the center, whereby the water is distributed substantially uniformly among the channels. 